Fix FMS collate for >9999 files

[aidanheerdegen]

Closes #309

Modified payu.models.fms.get_uncollated_files to support > 9999 files.

Added tests.

[pep8speaks]

Hello @aidanheerdegen! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file test/models/test_fms.py:

Line 19:1: E302 expected 2 blank lines, found 1
Line 25:1: E302 expected 2 blank lines, found 1
Line 28:1: E302 expected 2 blank lines, found 1
Line 38:1: E302 expected 2 blank lines, found 1
Line 47:1: E302 expected 2 blank lines, found 1
Line 50:32: W291 trailing whitespace
Line 57:1: E302 expected 2 blank lines, found 1
Line 62:1: E302 expected 2 blank lines, found 1
Line 64:28: E231 missing whitespace after ','
Line 69:28: E231 missing whitespace after ','
Line 71:28: E231 missing whitespace after ','
Line 76:28: E231 missing whitespace after ','
Line 80:25: E231 missing whitespace after ','
Line 85:28: E231 missing whitespace after ','
Line 90:30: E231 missing whitespace after ','
Line 95:28: E231 missing whitespace after ','
Line 95:55: W292 no newline at end of file

Comment last updated at 2021-09-03 06:59:01 UTC

[coveralls]

Coverage increased (+0.1%) to 42.326% when pulling e9372f3 on issue-309 into 9348acd on master.

[aidanheerdegen]

As this is currently stopping work I will merge shortly, so speak up if anyone (@marshallward @aekiss ?) spots any problems

[aekiss]

looks fine to me @aidanheerdegen